Modern society strongly relies on secret information for authentication. However, keeping information secret and accessible is exceedingly difficult in modern society. We experimentally demonstrate Quantum-Secure Authentication (QSA) that does not require keeping secret information but relies on an optical Physical Unclonable Function (PUF) as a key . The method relies on shaping a complex wavefront containing only a few photons, on average. It naturally confronts us with the question how much information can realistically be stored in spatial coding of single photons. We have recently demonstrated a record 10.5 bit/photon .
Fig 1: A powerful green laser beam travelling through a maze made from a random collection of mirror, beam splitters and prisms. It illustrates the complex path that light takes through a multiple-scattering medium . QSA is an intriguing application of “Adaptive Quantum Optics”, the combination of quantum optics and adaptive optical methods counteracting or even exploiting disorder. We have also demonstrated that with wavefront modulators, multiple-scattering materials can be turned into programmable linear optical networks. In such a network we demonstrate programmable two-photon quantum interference . More recently we have combined this with transmission through multimode fibers to realize a new form of quantum communication .  Quantum-secure authentication of a physical unclonable key, S. A. Goorden, M. Horstmann, A. P. Mosk, B. Škorić, and P. W. H. Pinkse, Optica 1, 421-424 (2014).  Transmitting more than 10 bit with a single photon, T. B. H. Tentrup, T. Hummel, T. A. W. Wolterink, R. Uppu, A. P. Mosk, and P. W. H. Pinkse, Opt. Express 25, 2826 (2017).  Programmable two-photon quantum interference in 103 channels in opaque scattering media, T. A. W. Wolterink, R. Uppu, G. Ctistis, W. L. Vos, K. J. Boller, and P. W. H. Pinkse, Phys. Rev. A 93, 053817 (2016).  Multimode-fiber-based high-dimensional quantum secure communication, L. V. Amitonova, T. B. H. Tentrup, I. M. Vellekoop, and P. W. H. Pinkse, ArXiv 1801.07180.